Examining the Dietary Behavior of Australopithecus robustus and Rossil Primates from Swartkrans, South Africa Using Low-Magnification Stereomicroscopy of Dental Microwear


The Pleistocene cave of Swartkrans, South Africa, dated to 1.8 million years ago, preserves the early hominin Australopithecus robustus as well as the remains of several extinct primate species including Parapapio jonesi and Dinopithecus ingens. Dental casts of well-preserved fossilized teeth from Swartkrans exhibit microwear features which are indicative of distinct masticatory behaviors, such as rotary chewing or crushing, as well as the type of foods consumed and the degree of hard-object consumption. A principal components (PC) analysis of six microwear features from four individuals of each taxon from Swartkrans Cave using a stereomicroscope at 35X with an external moveable light source shows distinct differences in dietary behavior. Australopithecus robustus loads positive on PC1 (43.7%) from the prevalence of fine, coarse and hypercoarse scratches. In contrast, Dinopithecus ingens is positioned primarily on the opposite pole due to small and large pits. Parapapio jonesi lies between these two extremes. On PC2 (17.2%), Australopithecus robustus and Parpapio jonesi are separated from Dinopithecus ingens and one Australopithecus robustus specimen, SK 79, on the basis of hypercoarse scratches and puncture pits in the latter. These results indicate a dietary niche partitioning at Swartkrans. Most Australopithecus robustus probably consumed grasses, leaves, herbs and other tough, low quality foods, whereas Dinopithecus ingens relied on a relatively coarse diet which may have included substantial amounts of grit, likely from adhesion to underground storage organs, or other hard and brittle resources. Parapapio jonesi appears to have been a generalist and most likely consumed some tough and hard foods but not to the extent observed in the other taxa preserved at Swartkrans.

This document is currently not available here.